Emergency signal system for motor vehicles



M. L. JACOBS ET AL 2 Sheets-Sheet 1 EMERGENCY SIGNAL SYSTEM FOR MOTORVEHICLES #4f/Fria (/5 ,/,46055 Joa-"PH /71/,46055 June 19, 1956 M. L.JACOBS ET AL Filed March 8, 1954 EMERGENCY SIGNAL SYSTEM FOR MOTORVEHICLES 70 /YZ/ff 2 sheetssneet 2 /f/@ 5W/ff!! H fba/ z// f afl `6 V il l iwf/M l ,47m/Mfrs limited States Fatent EMERGENCY SIGNAL SYSTEM FORMOTOR VEHICLES Marcellus L. Jacobs and Joseph H. Jacobs,

This invention relates to emergency, illuminated signal systems formotor vehicles adapted to very effectively warn the drivers offollowing, as well as cross-traffic drivers, that a vehicle is coming orhas come to a rapid or emergency stop.

At the present, conventional motor vehicles employ stop Warning lightsat both sides of the rear of a car which become illuminated at aconstant intensity whenever the driver begins to apply brake control.Such a system, of course, alerts the drivers of following cars but nomeans or system is provided to in any wayv indicate the degree ofbraking or the rapid deceleration of the leading vehicle. Many accidentsoccur because the driver of the following vehicle has no knowledge thatthe vehicle ahead has made a full emergency stop and, in other instanceswhere the following driver is cautious, valuable time is lost because ofa failure to indicate full braking or a rapid stop and thereaftercontinuance of travel.

It is an object of our present invention to provide a comparativelysimple, thoroughly reliable and efficient emergency orrapid-stop-indicating system, which may Well be correlated with theconventional electrical stop light systems of motor vehicles, and which,through intensive illumination with a special warning light at the rearof a car, will necessarily arrest the attention of following driversand/or drivers on crossroads, warning them that a motor vehicle ismaking or has made an emergency stop.

Another object is the provision of an illuminated electrical emergencysignaling system of the class described wherein the emergency signallight once actuated or illuminated through rapid deceleration of the carwill be maintained for warning until the driver completely releasesbrake control.

Another object is the provision of an illuminated warning system of theclass described wherein compensation for required variance in Warninglight intensity for both night and day driving is effectively andsubstantially automatically eiected.

A still further object is the provision in a system of the classdescribed of a conveniently and manually controlled asher switchinterposed in the main circuit of the rapid stop signaling lamp wherebyif a car must be stopped for some time at the side of a road or isdisabled, drivers of other cars going in both directions may beelectively warned.

In one form of our invention the emergency warning circuit is initiallyset in operation through the medium4 of a so-called inertia switch ofeiective but very simple construction while in another form of ourinvention` initial operation of the warning circuit is actuated by aspecial rapid-stop or high pressure brake switch, which is closed onlywhen unusual braking pressure is applied by the driver for the purposeof making an emergency stop. In both forms of the invention it isimportant to the closely cooperating combination of elements that aholding switch be employed to prevent discontinuance of ice theemergency signal upon release of high pressure brake control.

The foregoing and other objects and advantages of our invention willmore fully appear from the following description made in connection withthe accompanying drawings wherein like reference characters refer tosimilar parts through the several views and in which:

Fig. 1 is an electrical system diagram showing the circuits andcomponents of one form of our invention;

Figure 2 is a rear view of a motor vehicle equipped with our system andshowing a suitable location and the structure of this special emergencystop light;

Figure 3 is an electrical diagram showing the circuits and components of.another form of our invention wherein the main emergency signalingcircuit is initially actuated through a high pressure brake switch; and

Figure 4 is a sectional view of a high pressure brake switch used inconnection with the modied form of the invention shown in Fig. 3.

Referring now to the form of our invention diagrammatically illustratedin Figure l of the drawings, the usual stop light circuit for a motorvehicle is diagrammed at the left side of Figure l, including a pair ofconventional stop lights 5, usually mounted at the rear and side cornersof an automobile body as in the rear fenders and electrically connectedby a conductor 6 with a line 7 in circuit with a conventionalbrake-light switch B. S. Switch B. S. is, of course, applied to thebrake pedal and is actuated immediately upon initial pressure of thepedal to energize the conventional brake lights 5. These lights remainon as long as the brake pedal is depressed and their intensity does notvary in accordance with the pressure applied. The circuit describedincludes a source of electrical energy such as the storage battery Bcarried by the car, one electrode of which is usually grounded on thecar frame.

In the form of the invention diagrammed in Figure l, a main, rapid-stopor emergency-indicating circuit is shown for automatically energizing aspecial intensied warning light L, which light, as shown in Figure 2, ispreferably positioned in a left, attention-commanding position at therear of the car, as upon the left rear fender. Lamp L is preferablyprovided with two separate interconnected iilaments f-l and f-2, one ofwhich is adapted to give a substantially more intense illumination thanthe other.

The operating circuit for emergency light L is controlled, as shown inFigure 1, by an inertia-actuated electrical switch wherein the spacedcontacts are normally opened but will be electrically interconnectedthrough sudden and rapid deceleration of the speed and travel of themotor vehicle. A simple and highly eiiicient inertia switch I. S. forthe purpose intended is illustrated in Figure 1, comprising a iixedlymounted mercury tube 8 supported by a suitable bracket 9 from anupstanding support such as the dashboard D of the motor vehicle.Electrical terminals t-l and t-Z are disposed within the hermeticallysealed mercury tube and the tube is declined forwardly, as shown, sothat said terminals will, in normal driving and starting, not be coveredby the globule of mercury therein. With the proper inclination of themercury tube 8, when the car in rapid travel is suddenly decelerated byapplying heavy pressure to the brake control, the mercury globulemomentarily moves forwardly and upwardly to cover and interconnect theterminals of contacts t-1 and t2, thereby energizing a holding switch inthe circuit. As shown, the terminal 2 2 of the inertia switch iselectrically connected with the lead wire 7 which is in the conventionaland the herein auxiliary circuit for the conventional brake lights 5.The terminal t-l of the mercury switch is connected with a conductor 10of the emergency warning circuit which is, in turn,

- headlight switch and battery (not shown).

electrically connected with the coil 11a of a solenoidholding switch 11,having a hinged armature plate or arm 11b. The other side of coil 11a,as shown, is grounded to the frame of the motor vehicle. A suitable'electrical resistance element 12 is interposed between ,the lead wire 7and the connection vof conductor il) with the electro-magnetic coil lla.Current flowing through resistor 12 is sucient to hold relay 11energized and 0.11' tacts 11b thereof closed after therelay has beeninitially energized by current through switch l. S.

When the holding switch 11 is closed, electrical energy will beVtransmitted through a conductor 13 to the vinput terminal of lament f-gof the signal lamp L, and then grounded, as shown, in Figure l to theframe of ythe vehicle. lThe input end of the secondV filament f-l of theemergency light L is connected by a wire or conductor 1 4 aV Contactmounted on the swinging armature 15a of an electro-magnetic holdingswitch 15 connected in the conventional headlight circuit. Holdingswitch 15 has 'an electro-magnetic coil 15b which is velectricallyconnected by a wire 16V with the conventional The xed contact of vthe:holding switch I5 is electrically connected by a wire 17 with theconductor 1S which supplies the first ilament f -Z of the emergencylight L. Y

. A pair of brake-indicating dashboard lights vi8 and 19 are suitablymounted on the dashboard respectively con-Y nected to conductors 6andli) and grounded to the frame of the car for indicating to the driverwhen the usual stop lights are illuminated. l

' A manually actuated emergency asher switch E is interposed in thecircuit supplying the emergency lightV L, as shown, being bridged acrossthe supplyconductors 13 and 14. Flasher E is preferably, mounted onornear the dashboard of thecar and hasv a tumbler or movable contact, asclearly shown in the diagram of Figure 1.

In operation, a motor vehicle with our safety signal system installedtherein will operate in conventionalfashion both at'night and in thedaytime insofar as conventional stop lights, headlights and turn signalsare concerned in usual driving. No attention or manual-setting of thesystem is required for rapid stop warning since theV interconnection otthe emergency circuit with the standard brake light switch circuit andwith the emergency switch I. S. is always ready for actuation.

In the daytime when the headlight circuit is not normally energized,both iilarnents f-l and f-Z will be interconnected through lthe leadwires i4 and 1:3 to cause energization thereof when the driver applieshigh pressure braking power as in an emergency to. avert an accii dentor an object. At such time, the mercury globule in inertia switch l. S.due to the very fast deceleration of the car, advances, coveringcontacts tf1 and t-Z and momentarily at least interconnecting the sameto energize the holding switch 11 which, in turn, interconnects thesource of electrical Venergy to the filaments ot the emergency orVrapid-stop-indicating light L. This holding switch 11 will maintain thecircuit tothe emergency light L closed until the brake pedal or, controlis fully released.

During daytime operation, filament -l will be connected in parallel withfilament f-Z through lines 14 and 17 and `the normally closed contacts15a of relay 15 which, of course, will be de-energized when theheadlight circuit is open. Filament f-Z and filament fare energizedthrough the contacts 11b of relay il and through line 20 whichisconnected to the battery when the coil 11n of relay .11 is energizedlthrough conductors 1t?. and 7 and through inertia switch l. S. when thesame is closed by rapid deceleration of the vehicle and through brakeswitch B. S.v when the brakes of the vehicle are aIPliai after Gail.1,111 has. been' initially ener-sized t0`V At night when the headlights5 areilluminated, the magnetic Yholding switch 1'5 operates to thenbreak connection of the armature 15a with the xed contact of conductor17,V thus cutting out electrical connection through wire 14 of one ofthe filaments f-l of emergency light L. A lesser light intensity atnight is naturally required than in the daytime and our system, as hasbeen described, automatically makesr the necessary compensation fornight `and day driving. The intensity and location of the emergencylight L indicates to following drivers as well as to tratic on'sideroads that the car giving this emergency signal is applying full brakingpressure for a very rapid stop and this Aspecial signal is not'Vdiscontinued until the driver has fully released theV brake control. Y

In night time operation when the headlights are on and the headlightcircuit is closed, filament f-Z of the emergency light L is operated inan identical manner to the daytime operation thereof. Energization ofthe head-V light circuit will energize the coil 15b of relay l5V to openthe contactslSa thereof and thereby de-energize iilament f-l of theemergency light L. Filament f-.l is rie-energized to permit theemergency ilasherY E to 'be rendered operative for hashing lilamentf--l` during rapid deceleration in night time use. Filament f-l will beintenv In Figure 3, we diagrammatically illustrate a somewhat diierentform of our invention Where, in lieuY ofV the emergency switch` of theform of Figure l, a special high pressure brake switch H. P. is employedhaving the same relationship to theV holding switch 11 as has theinertia switch in the irst form described. A suitable form of highpressure or rapid stop indicating brake switch is illustrated in Figure4,V employing a small ovoid housing 21 connected at its lower end as bythe small conduit 21C with the master'cylinder of the hydraulic brakingsystem of the car (not shown). Shell 21 has a centrally disposed,transverse, exible diaphragm 21a which is reinforced at its centralportion and'carries on its upper side a movable contact 2lb. Thediaphragm is sealed at its edges with housing 21 and, as shown, carriesan inverted, U-.shaped element 22 on the upper side thereof which isurged downwardly by a coil spring 2 3 seated at its lower end on theU-shaped member and interposed between the same and the. adjustablecollar 24a of a threaded adjustment nut 24. The adjustment nut 24threadedly engages the tapped bore in the upper air-containing en dofthe small housing 21. A short pin projects downwardly from the collar24a for properly retaining the spring. With such adjustment, a variabletension may be imposed upon spring 23 to counter-.balance the. fluidpressure againsty the underside of' the diaphragm 21a.

The small contact 2lb. is electrically connected with supply conductor2S. A laterally extending contact 26a is mounted in the upper portion.of shell 21 extending radially inwardly andY positioned to be engaged bymovable contact 21 b, said contact being insulated fromA the shell 21.This Contact is connected to the wire 1Qfwhich, in turn, is connectedtov energize the holding; switch 1 1.

The operation of the second form of 0111 invention' is Similar to that@fille first forthwith the exception that the emergency orrapidrstonndicatine citant is actuated i bythe contacts of the,high-pressure switchH. Pf. associated. with the brake pedal itself.

With both. forms of ourA invenfian,Y there is a. close and. valuable.coordination betweenA Vthe conventional rear` stop lights of the.motorvehicle and ourffrapid stop indicating signal. ln driving,following drivers are alerted by the usual illumination of theconventional stop lights 5 as soon as the driver of the leading Vehicleapplies or begins to apply his brakes. Thereafter, if the leadingvehicle applies high pressure braking power, the emergency light L withintensive illumination is energized, advising following trafic as wellas traic on side roads as to the degree of braking and emergency use ofbrakes for a sudden stop. This enables the drivers of following vehiclesto properly gauge spacing on the highway and to determine the degree ofbraking applied by the leading vehicle and consequently loss of time,and better spacing of vehicles on a highway is made possible with theaverting of many serious accidents. In other words, following traiic isalerted when brakes are first applied, and then warned immediately uponrapid stop of the leading vehicle with the elimination of successivehigh pressure braking by the following vehicles, starts and stops andimproper spacing.

It will, of course, be understood that various changes may be made inthe form, details, arrangement and proportions of the parts withoutIdeparting from the scope of our invention.

What we claim is:

1. A safety signal system for motor vehicles provided with theconventional brake controls, having in combination an emergencyelectrical signalling light adapted to furnish intensive illuminationand disposed in a predetermined position at the rear of a motor Vehicle,an electrical circuit including said signal light, a switch in saidcircuit actuated only when said Vehicle very rapidly decelerates itsspeed, and a control switch in said circuit actuated by said rstmentioned switch and switch holding means adapted to be connected withsuch a brake control to maintain said circuit closed through said signallamp until the brake control is completely released.

2. In an illuminated safety signal system for a motor vehicle of thetype having a headlight circuit and a brakeoperated stop light circuit,the combination of an emergency electric signal light disposed at therear of such a motor vehicle and having several filaments forilluminating said light at at least two dilerent intensities; anelectrical circuit separately connected to each of said laments forenergizing the same and including a control switch in said circuit forclosing the same, circuit means for operating said control switch andincluding an inertia switch actuated only when such a vehicle veryrapidly decelerates and thereby causes illumination of said light, aholding circuit adapted to be connected to and energized by such a stoplight circuit for maintaining said control switch closed until thevehicle brake is completely released, an auxiliary switch connected toone of said filaments and an auxiliary circuit adapted to be connectedto such a headlight circuit and being associated with said auxiliaryswitch for operating the same and for opening said auxiliary switch whenthe headlight circuit is energized, whereby said emergency light will beilluminated with less intensity Y at night when the headlights are onthan in the daytime when the headlights are and when a quick stop ismade.

3. The structure recited in claim 2 and including a iiasher circuitconnected to said last mentioned filament for intermittently energizingthe same to cause intermittent illumination of the filament even thoughSaid auxiliary switch is open when the headlights are on and the driversof following vehicles will thereby be apprised er' an emergencysituation.

4. In combination with the conventional stop light system of a motorvehicle wherein the brake-operated switch controls a switch light, anemergency electric signal circuit adapted to be connected to such asystem and including an emergency light connected in said circuit anddisposed in a permanent position at the rear of the motor vehicle, acontrol switch connected with said emergency light and adapted to closethe circuit thereto for energizthe same, circuit means associated withsaid switch for operating the same and including an inertia switchoperable only when said vehicle very rapidly decelerates and alsoincluding a holding circuit adapted to be connected to such abrake-operated switch for holding said control switch, when closed, aslong as the brake of such a vehicle is applied, whereby said emergencylight will be illuminated when such a vehicle is making a quick stop andthereafter until the brake is completely released to warn drivers offollowing vehicles of an emergency situation.

5. The structure set forth in claim 4 wherein said inertia switchcomprises an elongated mercury tube switch disposed longitudinaliy ofthe motor vehicle, said mercury tube switch being inclined and havingforward and rear ends, said forward end being elevated relative to saidrear end whereby to carry the mercury in said rear end during constantvelocity travel of the vehicle, and said mercury switch tube having apair oi electrical contacts therein disposed in spaced relation fromsaid rear end and toward said front end and said contacts beingpositionedV for immersion in said mercury when the same moves toward thefront end of said mercury tube switch, whereby to close said switch uponsudden and rapid deceleration of the vehicle and thereby operate saidemergency light.

References Cited in the tile of this patent UNITED STATES PATENTS1,142,852 Simon June 15, 1915 1,263,902 Kiefer Apr. 23, 1918 1,517,669Deane Dec. 2, 1924 1,717,617 Moore lune 18, 1929 1,946,759 Preston Feb.13, 1934 2,260,680 Nelson Oct. 28, 1941 2,339,687 Doane Ian. 18, 1944

